The present invention relates to a derivative of 1,5-diphenyl-1H-1,2,4-triazole-3-carboxamide utilized as an active ingredient of herbicidal composition, and a herbicidal composition containing the derivative as an active ingredient.
Rice plant, wheat and corn are the important crop plants. In order to protect these crop plants from the injury of weeds and for yielding a good harvest of crops, the use of herbicide(s) is indispensable, and the development of a compound, which has an excellent selective herbicidal activity of killing only weeds without damaging the useful crop plants such as rice plant, wheat, corn etc., has been strongly demanded.
Although the derivatives of 1,5-diphenyl-1H-1,2,4-triazole-3-carboxamide and herbicidal activity thereof have been hitherto reported in Japanese Patent Applications Laying-Open (KOKAI) Nos. 57-193406 (1982), 57-193466 (1982) and 58-185572 (1983), etc., the herbicidal activity of each of the derivatives of 1,5-diphenyl-1H-1,2,4-triazole-3-carboxamide disclosed is not fully satisfiable and the selectivity thereof cannot be said to be excellent.
As a result of the present inventors' studies for developing a compound which shows an excellent herbicidal activity and at the same time, does not damage the useful crop plants such as rice plant, wheat, corn, etc., it has been found by the present inventors that a novel derivative of 1,5-diphenyl-1H-1,2,4-triazole-3-carboxamide represented by the following formula (I): ##STR2## wherein R.sup.1 represents a straight-chain alkyl of 2 to 10 carbon atoms, a branched-chain alkyl or cycloalkyl of 3 to 10 carbon atoms, a (cycloalkyl)alkyl group of 4 to 10 carbon atoms, a non-substituted- or halogen-substituted phenyl, an aralkyl of 7 to 9 carbon atoms, an alkenyl of 3 to 6 carbon atoms or an alkyl of 2 to 10 carbon atoms, which has been substituted by 1 to 19 fluorine atoms and R.sup.2 represents a fluorine atom, a chlorine atom, a methyl or a methoxy, has an excellent selective herbicidal activity, and on the basis of this finding, the present inventors have achieved the present invention.
Namely, the object of the present invention lies in providing a novel derivative of 1,5-diphenyl-1H-1,2,4-triazole-3-carboxamide, which shows an excellent herbicidal activity to the graminous weeds and broad-leaved weeds, particularly to broad-leaved weeds and on the other hand, shows practically no phytotoxicity to the crop plants such as rice plant, wheat, corn, etc., and a herbicidal composition containing the derivative as an active ingredient.